Bag size question: Berthoud GB28 versus GB25?

[Rob Klurfield]

Hi All. Looking for some expert advice on which size Gilles Berthoud bag will work best for me -- GB25 or GB28.

As my frame is a small size Crust Lightning Bolt (51.2 ctc seat tube 54.0 top tube), I think the larger bag might a bit too large (visually / aesthetically), but I wouldn't mind the extra capacity.

Here's a couple of photos of my rack and decaleur set up, which lead me to wonder if I'm between sizes and might need a drop bolt kit from Rene Herse if I opt for the smaller bag.

Any suggestions are welcome.

I'd prefer the Berthoud bag, but I am open to considering a Ruthworks or Waxwing if the numbers dictate that a custom bag will fit better. I like the Berthoud features and to duplicate them on the Ruthworks or Waxwing would cost more (leather trim, 3D side pockets, etc.) and I am a cheapskate (IMHO, all three companies make really attractive products).

Thanks!

Rob

[Evan Estern]

Hi Rob,

Here is a photo of a GB 28 on my bike.  I'm using the RH decaleur and CP1 rack, and the if I put a ruler in the same place as you I get the same measurement--9" from rack to "top" of decaleur.  The GB 28 is about 10" tall.  I use a 10cm stem and that puts the bag a bit too far forwards to hang plumb unless it's fully loaded.  The 25 might fit slightly better on both our bikes. 

[Rob Klurfield]

Evan, thanks for the pictures and commentary. The GB25 is about 8 inches high. At that height, wouldn't the bag be too short to rest on the rack without using one of RH's drop bolt kits? Rob

[Rob Klurfield]

Evan, one more question: what kind of fasteners -- nuts & bolts -- do you use to affix the bag to the decaleur? Does RH include those with the bags? Thx! Rob

Anyone else, please weigh in with opinions, insights, advice, photos, etc.

[Mitch Harris]

So close, Rob. Just measured my bikes at 8.5" for that same dimension, CP-1 rack to top of decaleur tubes. I use a GB28 size bag and get good fit with this 8.5 inches without any of the flop-over onto the fender that Evan's photos show.  For comparison's sake, the decaleur pin rail on my GB28 is attached even with upper edge of the leather bag-top strip, and the lid of the bag pretty even with the bars. 

To your question I was going to recommend going with the larger GB28 size until Evan posted his photos which is really helpful if you wanted to avoid the flopover effect onto the fender. I guess it matters what inside the bag is leaning on the fender, like you wouldn't want a heavy tool kit leaning on and bouncing on the fender. Perhaps that half inch difference between 8" and 8.5" is enough to make the difference but Evan's bag is also leaned forward a bit, which also encourages that spill over, and the CP-1, a great rack, is pretty short compared to a Nitto 32f or VO Randonneur. 

At the same time, I think Evan's set up looks great, and according to Rebour drawings and photos from Golden Age, etc, this is the way it was often done in those years when this front-back-on-rack/dec was established. That leaned forward bag touching fender looks almost standard in old photos. Not saying that's a reason to use it--you'd choose if for functional preference I think--but just saying aesthetics (as you mention) may be not a reason to avoid it per se. 

Aside from the specific bag-fit questions, there may be a question which size to go with if you could use either equally well. I used a GB25 for the first few years I road with front-bag and then switched to GB28. Couple reasons to go with the larger bag if it works out and if you like it. The larger 28 bag seems like it has no drawback compared to the 25 if both work, what tiny extra weight there would be is mainly an inch of cotton duck. There seems to be no difference to me in how the two bag sizes affect wind while riding, cross-wind, etc. I had but the 28 and 25 available to me for a year of riding and when I'd start a ride with the 28 mostly empty I'd think "i should have put the 25 on instead," but while riding, and if I did switch to the 25 for the next ride, I could feel no difference in the wind, from front or side. The GB28 (or another larger bag) is on my bike for every ride, usually mostly empty and doesn't affect handling. I got the GB25 early on when I thought a front-bag would be a  nuisance and it should be below the bar, but as I've learned better, I prefer the bag even with or a little higher that bar top. I also regularly use a OAC Docena (Swift made) that is a bit higher than my bars and I realized it feels right that way, gives me the most load-carry versatility (and looks right to me too). This only become more true as a GB bag breaks in over the years and miles, becomes more rumpled and faded, and develops its own inevitable sag. It still holds as much as it does when new and perky, but after a few years an unloaded GB28 looks smaller than it does new.

Here is an idea to consider for your situation, and apologies if it breaks too many decaleur rules. I recently built up a Jack Taylor I'd had in storage too long, and adapted the CP-1 rack to work with the braze-on Racers. Because Racer pivots are a little higher on the fork than Raid/RH CP pivots, the CP-1 sits a little higher in the rear and slopes down a little toward the front in order for the CP-1 legs to reach. (I've found no functional problems with this, the remedy to get it level would require a custom rack, and in the meantime this CP-1 is already bent to that shape, so that's what I'm going with for the time being.) 

Because the rack on the Jack Taylor is higher in the rear than designed (and also due to Jack Taylor's fit), this bike had only 7" from rear rack deck to decaleur top installed the usual way. When I popped the GB28 into the decaleur for first ride, the pins didn't go all the way in. I set up a decaleur to support no weight at all, theoretically, but this 1.5" too low dec didn't support the bag side-to-side or front-to-rear very well. It occured to me to try the decaleur tubes pointing up instead, and it put them at exactly 8.5" and now supports the GB28 in the usual way. The bag lid sits a little higher than bar level, but in a way that looks right to me, and works well. The attached Jack Taylor photo doesn't show the decaleur fully but you can see the tubes are not hanging down where you'd expect them. 

Mitch

[Evan Estern]

IDK what RH includes with the bags as I bought mine elsewhere.  Myy RH decaleur included bolts, but you might need to get longer ones if you add a home made stiffener.  What I did for my set up was to take out the heavy plastic thing that came with my GB28 and replace it with a piece of 1" x 1/16" aluminum flat stock that I bought at my local hardware store.  I bent this into a "U" shape, drilled holes to match the RH decaleur and added velcro to mate to the velcro in the bag.  I used M3(I thnik) stainless steel button head machine screws with nylok nuts, again from the local hardware store.

I can't really speak to as to whether the 25 will be too short since I have never tried to fit one on this bike, but if it was me, I'd go for a 28 or something else in that size.  I often stuff mine beyond capacity and if anything wish it was bigger not smaller.  I think the 28 offers a good compromise in size and weight vs capacity.  The sag you see on the front rack goes away when the bag is loaded.  In the photos it was mostly empty except for a couple of spare tubes in the front pocket which made it droop forwards.

Mitch--that Jack Taylor looks beautiful!

[Rob Klurfield]

Mitch and Evan, thank you, thank you! I'm 99.999% sure I'll be ordering a GB28 this week. Guys, those bikes of yours are all beauties! Best, Rob

On Friday, May 15, 2020 at 11:16:59 AM UTC-4, Rob Klurfield wrote:

[Michael Arciero]

A couple of thoughts.

I am generally in favor of as large a bag as is practicable (have you ever once wished you had brought a smaller bag rather than a larger?? Sort of like wishing you had a bigger lowest gear, rather than a smaller one) but one possible reason for favoring a smaller bag is that it *may* be easier to select items if you dont have to dig far down, especially given that the Berthoud has shallow depth compared to other bags. 

One reason I went with shorter stem on my bike and set up is to reduce wheel flop affect. Though actual wheel flop is independent  of bag position, locating the bag farther forward will increase the moment about the steering axis and affect handling more. Shorter stem addresses the leaning forward issue as well. The trade-off is longer top tube which *may* be more shimmy prone.  It's sort of a wash for me as I have an Ozette which at 7.5 inches depth extends pretty far. I was considering a Berthoud or, more likely a Waxwing, to get less depth as well as address a few other details. The Ozette works fine though and I have gotten used to having that increased depth. Yet another consideration is that with short stem and bag located rearward you may get knee interference with the bag when out of the saddle. This happens to me once in a while but I dont mind it. Another example of how all of these things work with and affect each other. 

 

[Michael Arciero]

...another consideration is that with a bag height lower than the bar tops you wont need as much room for hands and so can locate the bag a bit farther back, though now accessing it may be more finicky. I'm shooting for top about level with bar tops, as Mitch indicated.

[Evan Estern]

If the top of the bag is lower than the handlebars there is a chance that without thinking you could try and get into the bag by reaching under the bars and actually get your hand stuck.  Not the best feeling--don't ask me how I know.

[David Parsons]

On Tuesday, May 19, 2020 at 5:30:20 PM UTC-7, Evan Estern wrote:

If the top of the bag is lower than the handlebars there is a chance that without thinking you could try and get into the bag by reaching under the bars and actually get your hand stuck. 

You get your hand hung up on the decaleur?

-david parsons

[Rob Klurfield]

I ordered the large size yesterday.

Can anyone suggest what type and size of nut, bolts and washers I'll need to affix the bag to the Rene Herse / Nitto / Hirose decaleur? I'm assuming I'll want some rust-proof, non-corroding fasteners -- ie, stainless steel or titanium. I bought this bike directly from Matt at Crust after the Philly Bike Show, where he had exhibited it as a pre-release prototype. I didn't think to ask him for the bolts, etc. at the time.

Thanks to everyone for all the helpful input. I'll post pictures when the bag arrives.

On Friday, May 15, 2020 at 11:16:59 AM UTC-4, Rob Klurfield wrote:

[Carl Lind]

I attached my bag to the RH decaleur with SS M5 screws, nylock nuts, fender washers on the inside.  This hardware may have been supplied with it, I can't recall.  

Carl

Seattle

[Evan Estern]

I initially said M3, but I just measured them and find that I used M5x15mm stainless button head machine screws with Nyloc nuts.  I did not use washers--not necessary with my setup. Screw length depends on whether you use a bag stiffener or not, I probably could go to the next size shorter or cut these off, but have not bothered. 

Here is an example, though in my case I used polished:   ttps://monsterbolts.com/products/socket-button-316-m5?_pos=2&_sid=fbabbeecc&_ss=r

[Rob Klurfield]

Wow. This is very helpful. Again, thanks to all!

[somervillebikes]

I've got an older GB28 and I did essentially the same thing as Evan... I used a flat aluminum stock (bent into a U) as stiffener and bolted it to the bag and decaleur. I also reasoned that since I had an aluminum stiffener running the entire width of the bag, I no longer needed the full width of the decaleur, in my case the heavy-ish SS bar stock VO variety. So I trimmed the SS bar stock down to short version and bolted that to the aluminum bar stock. It looks like this:

Anton

velolumino.com

[Eric Langley]

+1 Good thinking on trimming down the bar stock. I've also got an internal stiffener and I think I'll do the same on mine.

Eric

Chicago

[Evan Estern]

Yes, I wasn't paying attention and casually reached between handlebars and decaleur to get into the bag.  My hand was only stuck for a second or two, but it was a very unpleasant feeling--almost lost control of the bike.  I changed my setup immediately after that experience.

[Rob Klurfield]

M5s did the trick. 40-mile ride today was definitely enhanced by having room to carry a camera AND some fruit. Bag is great. Thanks everyone for the suggestions and advice. I'm very pleased.

On Friday, May 15, 2020 at 11:16:59 AM UTC-4, Rob Klurfield wrote:

[Pat Smith]

Looks great, I'm enjoying 650b + rando bag life myself with a Black Mountain Road+ and Restrap Rando (large). I only got this setup late March after the stay at home order hit, but I plan on using it for my commuter that takes longer, fun rides home, or to pick up some carryout for my wife and I (which I have done a lot after a 2.5 hour after work ride during the stay at home order). 

[Sam Scoville]

RH’s site states the gb28 will fit with a rack to handlebar/decaleur height of 25-29cm, but that the overall height of this bag is 27cm. How can this be? Is it supposed to deform to fit? I ask because I ordered one and the distance between my rack and decaleur is 28.5!

[Brad]

A certain amount of deformation to the plane at the bottom of the bag is part of how it works.   The wide v shape created works to prevent yaw.   If the bag, any bag, is perfectly square it will rotate on an axis in the center of the rack.  Some people solve this problem with under bag clips, but the bag drape also solves it.  A certain amount of forward lean also contributes to bag drape.  A feature, not a bug.